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Extension > Environment > Housing Technology > Moisture Management > Should I buy a home water treatment system?

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Should I buy a home water treatment system?

Wanda Olson, Extension housing technology specialist
Barbara Liukkonen, Extension water resources education coodinator

How you choose to improve your water quality depends upon your specific water conditions, health-related and nonhealth-related, and your household needs. A home water treatment system may or may not be the appropriate solution to a given water quality problem. This publication discusses several points you need to consider before buying or renting a water treatment system.

Is there a problem with my drinking water? To determine the quality of your water, it must be tested. If you have a public water supply, a water superintendent assures that tests are performed for many health-related contaminants and that the water supply meets minimum federal standards. To find out about the quality of your public water supply, contact your municipal water department or the Minnesota Department of Health. A public water supply may contain substances which affect taste, color, odor, or hardness but pose no health threat. Removal of these substances is usually the responsibility of the individual although municipalities may do so. Tests to detect these substances are available from water laboratories and water treatment dealers.

If you have a private water supply it's your responsibility to have it tested by a certified laboratory and to ensure that your drinking water meets recommended guidelines. Test results indicate whether or not your water supply is unhealthy for drinking, cooking, or bathing. Some Minnesota counties have a local laboratory which test for coliform bacteria and nitrates. Pesticide testing is done by specialized laboratories. Your community health service or county extension office can provide testing information. They will also provide much of the information necessary for you to correct any problems and help you review treatment technologies and maintenance programs.

carbon filter distillation reverse osmosis cation exchange
(home water softener)
anion exchange
Nitrate   x x   xa
Lead (from plumbing)   x x x  
Trihalomethanes (THMs)b x   c   
Many pesticides x x x    
Organic solvents x   c    
Coliform bacteria   x      
a Not recommended for nitrate removal if water supply contains high levels of sulfates
b Chlorinated organic chemicals
c Many reverse osmosis systems include a carbon filter that will remove these

What is the most appropriate way to correct a water quality problem? The way you choose to improve your water quality will depend upon which contaminants, if any, are found during testing and whether or not the source of these contaminants can be identified and eliminated. There are many water quality improvement methods. They include removing the source of contaminants, repairing or drilling a new well, connecting to a municipal or rural water supply, using bottled water, or installing a water treatment system. To put these in context, let's say your private water supply tests positive for coliform bacteria, a commonly used indicator of water contamination. You should correct the problem or use bottled water. Possible ways to correct the problem include shock chlorination of the water system, well repair, or removal of the source of contaminants. If shock chlorination or well repair does not correct the problem, you could disinfect water by boiling, continuous chlorination, or distillation. In such instances, the Minnesota Department of Health recommends boiling. Disinfection to kill disease-causing bacteria in a water source, however, should be a temporary measure used only until you have a new sanitary water supply. In some cases, a new well or different water supply may be the safest and most cost-effective solution. The table indicates which home water treatments are appropriate for different health-related contaminants.

How do I select the right water treatment system? Select the water treatment technology that suits your water conditions and delivers the amount of treated water your family needs. Generally, water treatment systems reduce concentrations rather than remove 100% of the contaminant. The system should be capable of reducing contaminants to a level that meets drinking water standards. The initial concentration of contaminants in your water will affect how much is removed and how soon your system will need service. Higher initial concentrations will probably result in higher levels in the treated water and will shorten the lives of filters and membranes. Check the manufacturer's specifications to determine if your water supply meets their operating conditions for that unit. Operating conditions include water temperature and pressure, total dissolved solids (TDS), iron, hardness, and chlorine.

Water treatment systems require monitoring and regular maintenance. For example, chlorinators require monitoring, distillation units need cleaning, and carbon filters must be replaced. Some systems have monitors or meters that indicate overall performance or how many gallons of water they have treated. Periodic water testing must be done for specific contaminants such as nitrate and coliform bacteria. It is important that you find out what type of maintenance is needed, by whom, and how often.

How are water treatment systems regulated? Federal and state governments do not certify water treatment equipment. Some states have product approval programs which require documentation of health-related and other claims made by the manufacturer of water treatment equipment. Other states additionally require approval of testing. The National Sanitation Foundation (NSF) is an independent laboratory which tests and certifies drinking water treatment systems. They establish national, uniform sanitation standards and criteria. Their seal indicates that a product or material complies with the relevant NSF standard. The Minnesota Department of Health recommends that any treatment system you buy have an NSF listing for the health-related contaminant of concern. Certified treatment systems are found in NSF Listings for Drinking Water Treatment Systems. The Water Quality Association publication, Validated Water Treatment Equipment Directory, also lists products in compliance with industry standards.

Listed below is a sampling of resources on water quality improvement, water treatment systems, and contaminants. Contact your county office of the University of Minnesota Extension Service, the Minnesota Department of Health, or the Minnesota Water Quality Association for further information and additional publications.

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